Used iSCSI to connect storage

iSCSI Target Configuration:

Step 0: Check the disk exists

lsblk

Step 1:Prepare LVM

[root@localhost ~]# vgcreate vgsan /dev/sdb
Physical volume "/dev/sdb" successfully created
Volume group "vgsan" successfully created
[root@localhost ~]# lvcreate -n lvsan -l 100%VG /dev/vgsan
Logical volume "lvsan" created.
[root@localhost ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root centos -wi-ao---- 6.67g
swap centos -wi-ao---- 820.00m
lvsan vgsan -wi-a----- 8.00g

Step 2:Install software

yum -y install targetcli

Step 3:Enter the targetcli interface

targetcli

Step 3.1: Configure backstores

/> cd backstores
First thing is to configure a backstorage device from our previously configured lvm volume
/backstores> block/ create block1 /dev/vgsan/lvsan

Step 3.2 :Configure IQN

IQN is the unique identifier of each iSCSI-target. IQN follows strict naming convention. It is in iqn.YY-MM.[inverse-DNS]:[target name] format. We have to make to sure to follow this convention, otherwise iqn creation will fail. To create iqn, move to the iscsi section.
/backstores> cd /iscsi
/iscsi> create iqn.2017-09.com.example:rock

Step 3.3 : Create ACL

Create an ACL to allow “client1” to access this target
/iscsi/iqn.20....example:rock> tpg1/acls/ create iqn.2017-09.com.example:client1

Step 3.4 : Create LUN

/iscsi/iqn.20....example:rock> tpg1/luns/ create /backstores/block/block1
Now we will go back to targetcli root to get a whole picture of what we created so far.

This completes the iscsi setup. Enter the command “exit” to come out of the targetcli prompt. this also saves the configuration.
/> exit

Step 4: Service & FW Configuration

systemctl start target
systemctl enable target
firewall-cmd --add-service=iscsi-target --zone=public --permanent
firewall-cmd --reload

references
https://rmahmood.tech/configuring-iscsi-on-centos-systems/

Initiator(Client) configuration:

Step 0: Check the disk exists

use the “lsblk” command , so later we can see the difference
lsblk

Step 1: Install Software

yum -y install iscsi-initiator-utils

Step 2: Edit or View InitiatorName

vi /etc/iscsi/initiatorname.iscsi
restart the iscsid service to configuration change to take effect.
systemctl restart iscsid

Step 3: Discover iscsi target

iscsiadm --mode discovery --type sendtargets --portal 192.168.1.56

Step 4: Log into the target

iscsiadm --mode node --targetname iqn.2017-09.com.example:rock --portal 192.168.1.56:3260 --login

Logout Target
iscsiadm --mode node --targetname iqn.2017-09.com.example:rock --portal 192.168.1.56:3260 --logout

Step 5: Specifically check the iscsi devices

lsblk

reference